This invention relates to switches for controlling electric appliances which have removable attachments such as vacuum cleaners wherein a dust collecting bag may be removed and a power head may be removed and replaced with an alternate version power head. In particular, this invention relates to electric switches having safety interlocks which opens the switch in the event one of the attachments is removed while the switch is in an ON condition. Still more particularly, the invention relates to switches of the aforementioned type which are insensitive to mechanical shock.
Switches of the aforementioned type utilized on vacuum cleaners or similar appliances are subjected to severe treatment. Attachments for the appliance are removed and replaced in, at best, a casual and often hurried manner. The switch is foot operated whereby the operating forces are strong and abrupt. As a result, operating mechanisms of previous switches of the aforementioned type have been made heavy, or strong, and therefore susceptible to fatigue, short life and breakage. Strong high energy operating mechanisms offset switch-opening operation of safety interlocks responsive to removal of an attachment, and therefore spring forces for the interlocks need to be increased. In use, the appliance may be jolted through collisions or falls, tending to inadvertently open the switch due to mechanical shock. Such tendency is intensified by strong, high energy operating mechanisms. To overcome the problems associated with high energy operating mechanisms, some previous switches of the aforesaid type have incorporated a multiplicity of discrete plunger operated snap action switches on a mounting plate. A mechanical lever system operating mechanism is also mounted on the mounting plate. This type of switch assembly requires a wiring harness and connector assembly, and is ordinarily more expensive than an integral switch package.